Damon,

Partial answers to your Q's: In a n.0 system with 'Large' speakers, the MC LFE content is sent (I believe) to the Main L/R only, not to any other Large speakers, so you can't work-out an 'optimum' number of Large speakers to replicate the sub level. Of course, taking the sub out disables the ability to indepenently alter the LFE content level relative to the other speakers - you're basically stuck with the abilities of your Main L/R speakers. Taking the sub out of the speaker array will cause the Xover box(es) to be greyed-out. My understanding of the M bass management is that Mono does give bass duplication below the Xover point with other speakers set to Large - in the G68 literature, M indicates this is not optimum. Centre setting is the alternative - with the MConfig with the G68, this automatically sets the centre speaker to Small.

Hope this helps (a little).

Andy

System 1: Control 15, 818v3, 800v3, 861v6, DSP8000SE, DSP7200HCSE, DSP8000.2, SW5500, HD621, 650BD, SkyHD, Radience XE, TH65PF12
System 2: MS200, 5200
System 3: MS200, F80
Sooloos: MD600: 2x3TB
On the move: Explorer 2, B&W P7W
Bedroom: F80+i80